To record data in external storage of a personal computer (PC), a mobile information terminal (PDA), a mobile telephone, etc., a removable medium of a portable memory card of an SD card, a memory stick, etc., made of nonvolatile semiconductor memory is widely used. Such a removable medium is formed with an area to record data for accessing and managing each file by formatting in a storage area like a hard disk, a floppy (registered trademark), disk, etc.
Formatting usually is performed conforming to the format standard determined considering the characteristic and the storage capacity of a removable medium. However, formatting performed by an operating system (OS) adopted for a personal computer, a mobile information terminal, etc., does not consider the characteristic of a removable medium. Thus, to format a removable medium in a host machine of a personal computer, a mobile information terminal, etc., formatting data and a formatting program need to be provided individually corresponding to the characteristic and the storage capacity of the removable medium. This puts a load on a host machine, particularly a small machine of a mobile information terminal, etc.
To solve the problem, hitherto, there has been an example wherein when an initialization command is sent from a host machine to a removable medium, formatting is performed in response to the formatting data stored in a system information storage section (for example, refer to Patent Document 1). There has also been an example wherein ROM previously storing data to be written at the formatting time and formatting information of a write position, etc., is provided and upon reception of a formatting instruction from a host machine, the formatting information is read from the ROM and formatting is performed (for example, refer to Patent Document 2).    Patent document 1: JP-A-2003-308241    Patent document 2: JP-A-2001-142761